Disazo dyestuff sulphuric acid ester

ABSTRACT

A dyestuff particularly for synthetic fibers of the formula ##STR1## wherein R 1  &#39; denotes hydrogen, methyl, ethyl or cyclohexyl, 
     R 2  &#39; denotes chlorine, methoxy, methyl, ethoxy, ethyl, trifluoromethyl or acetylamino, 
     R 3  &#39; denotes hydrogen, methyl, methoxy, ethyl and ethoxy, 
     R 4  &#39; denotes hydrogen, methyl, methoxy, ethyl and ethoxy, 
     R 5  &#39; denotes hydrogen, methyl, methoxy, chlorine or phenyl, 
     R 6  &#39; denotes hydrogen or methyl, 
     R 7  &#39; denotes hydrogen, methyl, ethyl, 2-hydroxyethyl, 2-hydroxypropyl and 2-hydroxybutyl, 
     m&#39; denotes 0 or 1 and 
     X denotes optionally branched C 2  to C 4  alkylene.

The invention relates to disazo dyestuffs which, in the form of the freeacid, correspond to the general formula ##STR2## wherein R₁ denoteshydrogen, optionally substituted alkyl, optionally substituted phenyl orcyclohexyl,

R₂ denotes chlorine, bromine, optionally substituted alkoxy, optionallysubstituted alkyl, acetylamino or benzoylamino,

R₃ and R₄ denote hydrogen, chlorine, bromine, optionally substitutedalkoxy or optionally substituted alkyl,

R₅ and R₆ denote hydrogen, optionally substituted alkyl, optionallysubstituted alkoxy, chlorine or optionally substituted phenyl,

R₇ denotes optionally substituted alkyl, optionally substitutedalkylcarbonyl, optionally substituted phenylcarbonyl, alkylsulphonyl oroptionally substituted phenylsulphonyl,

X denotes optionally branched C₂ -C₄ -alkylene, B denotes 1,4-phenylene,1,4-naphthylene or tetrahydro-1,4-naphthylene and

m denotes a number from 0-2,

and their preparation and use for dyeing synthetic fibre materials, inparticular those made of polyamides.

Preferred alkyl or alkoxy is alkyl or alkoxy with 1-4 C atoms, which canbe further substituted, for example, by fluorine, chlorine, cyano,hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄ -alkylcarbonyloxy or phenyl.Examples of suitable alkyl groups are --CH₃, --C₂ H₅, --C₃ H₇, --C₄ H₉,--C₂ H₄ CN, --CH₂ --C₆ H₅ and CF₃.

Examples of suitable alkoxy groups are --OCH₃, --OC₂ H₅, --OC₃ H₇, --OC₄H₉, --OCH₂ CH₂ OH and --OCH₂ C₆ H₅.

Examples of substituents of the phenyl radicals are C₁ --C₄ -alkoxy,chlorine, cyano, nitro and C₁ --C₄ -alkyl.

The sulphonamide group in the formula (I) is in the ortho-position,meta-position or para-position relative to the azo bridge, and theradical OR₇ is in the ortho-position or para-position relative to theazo bridge.

Preferred dyestuffs are those in which ##STR3## denotes 1,4-naphthyleneor tetrahydro-1,4-naphthylene which is not further substituted, or aradical of the formula ##STR4##

Particularly valuable dyestuffs are those in which m denotes 0 or 1, inparticular those of the formula ##STR5## wherein R₁ ' denotes hydrogen,methyl, ethyl or cyclohexyl,

R₂ ' denotes chlorine, methoxy, methyl, ethoxy, ethyl, trifluoromethylor acetylamino,

R₃ ' denotes hydrogen, methyl, methoxy, ethyl and ethoxy,

R₄ ' denotes hydrogen, methyl, methoxy, ethyl and ethoxy,

R₅ ' denotes hydrogen, methyl, methoxy, chlorine or phenyl,

R₆ ' denotes hydrogen or methyl,

R₇ ' denotes hydrogen, methyl, ethyl, 2-hydroxyethyl, 2-hydroxypropyland 2-hydroxybutyl,

m' denotes 0 or 1 and

X has the meaning indicated above.

Further particularly valuable dyestuffs are those of the formula##STR6## wherein B' denotes 1,4-naphthylene ortetrahydro-1,4-naphthylene and

R₁ ', R₂ ', R₅ ', R₆ ', R₇ ' and m' have the meaning indicated above.

The dyestuffs of the formula (I) are prepared in a known manner in whichamines of the formula ##STR7## wherein R₁, R₂, X and m have the meaningindicated above, are diazotised, the diazotisation products are reactedwith amines of the formula ##STR8## wherein R₃, R₄ and B have themeaning indicated above and

Z represents H or --CH₂ SO₃ H,

to give monoazo dyestuffs of the formula ##STR9## and, afterappropriately splitting off the group Z, if necessary, by alkaline oracid saponification, the monoazo dyestuffs thus obtained are diazotised,the diazotisation products are coupled with phenols, which couple in theortho-position or para-position relative to the OH group, of the formula##STR10## wherein R₅ and R₆ have the meaning indicated above, and thedisazo dyestuffs of the formula ##STR11## are then alkylated oracylated, the group R₇ being introduced.

Various methods are suitable for the preparation of the diazo components(IV). For example, it is possible to react sulphonic acid halides of theformulae (IX) to (XI) with amines of the formula (XII) and appropriatelyto saponify the acylamino group or reduce the nitro group. ##STR12##

A further possibility for the preparation of the sulphuric acidhalf-esters (IV) is in the form of esterification of hydroxy compoundsof the formula (XIII) to (XV), for example by introducing them intoconcentrated sulphuric acid, sulphuric acid monohydrate or oleum,preferably at temperatures between -5° C. and 20° C., and subsequentlystirring the mixture for several hours. ##STR13##

The sulphuric acid half-ester compounds are precipitated by dischargingthe mixture onto ice-water and are neutralised, whilst cooling, and canbe isolated, if appropriate after salting out with sodium chloride orpotassium chloride, by filtration.

The sulphuric acid half-esters from the compounds (XIV) and (XV) areconverted into the diazo components (IV) by saponification of the acylgroup or reduction of the nitro group.

The dyestuffs of the formula (I) according to the invention are alsoobtained by converting dyestuffs of the formula (XVI) into the sulphuricacid half-esters, analogously to the above process. ##STR14##

If this preparation method is used, R₇ should not contain an aliphatichydroxyl group, since otherwise two sulphuric acid half-ester radicalsare introduced into the molecule.

The introduction of the sulphuric acid half-ester group into themolecule can also be effected by esterification of the monoazointermediate stage (XVII) by the process indicated. ##STR15##

Examples which may be mentioned of suitable alkylating and acylatingagents for introducing the radical R₇ are dimethyl sulphate, diethylsulphate, methyl chloride, methyl iodide, ethyl chloride, propylbromide, isopropyl bromide, butyl iodide and benzyl bromide,p-toluenesulphonic acid methyl ester, benzenesulphonic acid ethyl esterand p-toluenesulphonic acid benzyl ester, and furthermore ethyleneoxide, 1,2-propylene oxide, 1,2- and 2,3-butylene oxide, styrene oxide,glycidol, glycidyl methyl ether, glycidyl acetate, glycidyl propionate,glycidyl metacrylate, glycidyl benzyl ether, epichlorohydrin,isobutylene oxide, acetic anhydride, acetyl chloride, chloroacetylchloride, propionic anhydride, propionyl chloride, butyric anhydride,isovaleryl chloride, benzoyl chloride, benzoic anhydride, 3-chlorobenzylchloride, 4-chlorobenzoyl chloride, 3-methylbenzoyl chloride,4-methylbenzoyl chloride, methanesulphonyl chloride, propanesulphonylchloride, butanesulphonyl chloride, benzenesulphonyl chloride, o-, m-and p-chlorobenzenesulphonyl chloride, o-, m- and p-toluenesulphonylchloride and the corresponding sulphonyl bromides.

The amines of the formula (IV) are diazotised by methods which are inthemselves known, preferably in aqueous, mineral acid solution usingsodium nitrite. The coupling of the diazoniun compounds of the amines ofthe formula (IV) with the coupling components of the formula (V) can becarried out by processes which are in themselves known, for example in aneutral to strongly acid, but preferably in a weakly acid, pH range inan aqueous or organic/aqueous medium.

The monoazo dyestuffs of the formula (IV) are isolated by known methods,for example by filtration or by salting out with a salt which is solublein aqueous solution, for example with NaCl or KCl, and subsequentfiltration. If coupling components of the formula (V) in which Z=--CH₂SO₃ H are employed, it is frequently necessary only to isolate themonoazo dyestuffs after the amino group of the coupling component hasbeen liberated by alkaline or acid saponification. However, intermediateisolation of the monoazo dyestuffs is not always necessary, they canalso be further diazotised without isolation.

The further diazotisation of the aminoazo dyestuffs (VI) in which Z=Hcan be carried out, for example, in an acid, aqueous dispersion usingsodium nitrite solution, it being possible for the diazotisationtemperatures to be between 0° and 30° C. In addition, aminoazo dyestuffsof the formula (VI) in which Z=H can also be indirectly diazotised bydissolving them under alkaline conditions, adding sodium nitritesolution and pouring the mixture into aqueous hydrochloric acid oradding hydrochloric acid.

The further diazotisation of the aminoazo dyestuffs (VI) can also becarried out in an aqueous/organic or purely organic medium, organicacids appropriately being added. Examples of organic solvents which maybe mentioned are dimethylformamide, dimethylsulphoxide, methylenechloride or chloroform.

The coupling of the diazotised aminoazo dyestuffs (VI) with the finalcomponents (VII) to give the diazo dyestuffs (VIII) is also carried outin the customary manner, preferably in an aqueous-alkaline medium. Thedisazo dyestuffs of the formula (VIII) can be isolated by simplefiltration, if appropriate after adding sodium chloride. If thedyestuffs are obtained in the impure form, they can be reprecipitated ina known manner from hot water, alkali being added if appropriate.

The reaction of the disazo dyestuffs (VIII) with the alkylating agentsto give the dyestuffs (I) is carried out in the customary manner, forexample in an aqueous, aqueous/organic or organic medium, alkali beingadded.

The sparingly soluble dyestuffs (I) can be rendered readilywater-soluble by mixing them with salts of strong bases and weak acids,for example trisodium phosphate, disodium hydrogen phosphate, sodiumtetraborate, sodium metaphosphate, sodium metasilicate, sodium carbonateor potassium carbonate, or with alkali metal hydroxides, such as sodiumhydroxide, potassium hydroxide or lithium hydroxide.

The new dyestuffs of the formula (I) can be isolated or can exist or canbe put to further use in the form of the free acid or as the alkalimetal salts or ammonium salts. Examples of suitable alkali metal salts,in which the hydrogen atom of the sulpho group is thus replaced by analkali metal cation, are the sodium salts, potassium salts or lithiumsalts.

The new dyestuffs are particularly suitable for dyeing and printingnatural and synthetic fibre materials containing amide groups, forexample those fibre materials made of wool, silk and polyamide, such aspoly-ε-caprolactam or the reaction product of hexamethylenediamine andadipic acid. The resulting dyeings, in particular those on polyamidematerials, are distinguished by good fastness properties, in particulargood fastness to wet processing and good fastness to light. The affinityunder neutral conditions and the combination properties with otherdyestuffs which are suitable for this material are also good. Thedyestuffs of the formula (I) are employed for dyeing either in the formof the free acid or as the alkali metal salt or ammonium salt.

In the examples which follow, percentages denote percentages by weight

EXAMPLE 1

221.5 g of 3-nitro-benzenesulphonyl chloride are introduced in portionsinto a solution of 150 g of sulphuric acid mono-2-amino-ethyl ester and0.6 liter of water at 60°-70° C. During this procedure, the pH value iscontinuously kept between 9.0 and 10.0 by adding 45% strength sodiumhydroxide solution dropwise. The mixture is subsequently stirred at60°-70° C. and pH 9.0 to 10.0 for 1 hour and then allowed to cool andthe resulting precipitate is filtered off. The precipitate is washedwith water and dried at 80° C. 305 g of sulphuric acidmono-N-(3-nitro-benzenesulphonyl)-2-amino-ethyl ester are obtained. Thisester is dissolved in 1.5 liters of dimethylformamide and hydrogenatedover Raney nickel. After subsequently filtering off the catalyst anddistilling off the solvent in vacuo, about 220 g of sulphuric acidmono-N-(3-aminophenylsulphonyl)-2-aminoethyl ester are obtained.##STR16##

EXAMPLE 2

216 g of 3-amino-N-(2-hydroxyethyl)-benzenesulphonamide are stirred into0.4 liter of sulphuric acid monohydrate at 0°-5° C., whilst cooling. Themixture is subsequently stirred, first at 0°-5° C. for 1 hour and thenat 15°-20° C. for 3 hours. The solution is then discharged onto about2.5 liters of ice-water, the temperature being kept below 5° C. Theresulting precipitate is allowed to settle, the sulphuric acid solutionis largely distilled off, the reaction product is filled up to a volumeof about 1 liter with ice-water, the mixture is neutralised by adding45.0% strength sodium hydroxide solution dropwise, whilst cooling, andthe resulting precipitate is filtered off. It is washed with a littlewater and can be employed in the subsequent diazotisation reaction as amoist paste. If the precipitate is dried, about 200 g of sulphuric acidmono-N-(3-amino-phenylsulphonyl)-2-aminoethyl ester are obtained.##STR17##

EXAMPLE 3

29.6 g of sulphuric acid mono-N-(3amino-phenylsulphonyl)-2-aminoethylester are dissolved in 200 ml of water, with the addition of 10%strength sodium hydroxide solution, and 7.0 g of sodium nitrite areadded. The solution thus obtained is allowed to run into 200 ml ofice/H₂ O and 35 g of concentrated hydrochloric acid and diazotisation iscarried out at 0°-5° C. in the course of 0.5 hour; thereafter, theexcess of nitrous acid is removed with amidosulphic acid and thediazonium salt suspension is allowed to run into a solution of 20.5 g ofanilino-methanesulphonic acid and 9 g of sodium bicarbonate in 100 ml ofwater at 0°-5° C., and the pH is kept between 5 and 7 by furtheraddition of sodium bicarbonate. After the coupling has ended, thedyestuff is salted out with sodium chloride, filtered off and washedwith saturated sodium chloride solution. The moist dyestuff pasts isstirred in 200 g of 7% strength sodium hydroxide solution at 80°-90° C.for 1 hour. After the splitting off of the sulphomethyl group has ended,the dyestuff is precipitated by adding sodium chloride, filtered off andwashed with saturated sodim chloride solution.

The aminoazo dyestuff thus obtained is dissolved in 500 ml of water, 7.0g of sodium nitrite are added, diazotization is carried out at 10°-20°C. in the course of 30 minutes by pouring the mixture onto 1,000 ml ofwater and 30 g of concentrated hydrochloric acid, and thereafter theexcess of nitrous acid is destroyed with amidosulphonic acid. Thediazonium salt suspension thus obtained is stirred into a solution of9.5 g of phenol and 4 g of sodium hydroxide in 200 parts of water at10°-20° C., and the pH is kept between 9 and 10 by adding 10% strengthsodium hydroxide solution. After the coupling has ended, the disazodyestuff is filtered off and dissolved at pH 8 in 500 ml of water and 2g of sodium carbonate. 30 g of propylene oxide are added dropwise tothis solution at 70° C. and the mixture is subsequently stirred at 70°C. for 6 hours. 80 g of sodium chloride are then added in portions, themixture is allowed to cool and the dyestuff which has precipitated isfiltered off. The dyestuff is washed with 3% strength sodium chloridesolution and dried at 50° C. in vacuo. It corresponds, in the form ofthe free acid, to the formula ##STR18## and dyes polyamide in yellowshades of good fastness properties from a weakly acid or neutral bath.

DYEING EXAMPLE

0.1 g of the dyestuff is dissolved hot in 100 ml of water, 5 ml of 10%strength ammonium acetate solution are added and the mixture is dilutedto a volume of 500 ml with water. 10 g of polyamide fibres areintroduced into the dyebath, the dyebath is brought to the boil in thecourse of 20 minutes, 4 ml of 10% strength acetic acid are added and thebath is kept at the boiling point for one hour. Thereafter, the fibresare rinsed, and dried at 70°-80° C.

If the procedure followed is as indicated in the above examples, usingthe initial components, intermediate components and final components andalkylating or acylating agents indicated in the table which follows,further disazo dyestuffs of the general formula (I) which dye polyamidein the yellow to scarlet shades indicated are obtained.

    __________________________________________________________________________    Ex-              Intermediate        Alkylating or acyl-                                                                      Colour                        ample                                                                             Starting component                                                                         component  Final component                                                                        ating agent                                                                              shade                         __________________________________________________________________________    4   Sulphuric acid mono-N-(2-                                                                  3-Amino-4-methoxy-                                                                       o-Cresol Dimethyl sulphate                                                                        orange                            amino-phenylsulphonyl)-2-                                                                  toluene                                                          aminoethyl ester                                                          5   Sulphuric acid mono-N-(2-                                                                  5,6,7,8-tetrahydro-                                                                      p-Cresol 1,2-Butylene oxide                                                                       orange                            amino-phenylsulphonyl)-2-                                                                  naphth-1-ylamine                                                 aminoethyl ester                                                          6   Sulphuric acid mono-N-(4-                                                                  2-Amino-anisole                                                                          1-Hydroxy-4-                                                                           --         yellow-                           amino-phenylsulphonyl)- tertiary butyl-     brown                             2-aminoethyl ester      benzene                                           7   Sulphuric acid mono-N-(4-                                                                  2-Amino-1,4-di-                                                                          m-Cresol Diethyl sulphate                                                                         scarlet                           amino-phenylsulphonyl)-                                                                    methoxy-benzene                                                  2-aminoethyl ester                                                        8   Sulphuric acid mono-N-(3-                                                                  1-Amino-2,5-                                                                             3-Hydroxy-1,2-                                                                         Ethylene oxide                                                                           orange                            amino-4-chloro-phenyl-                                                                     dimethyl-benzene                                                                         dimethyl-benzene                                      sulphonyl)-N-methyl-2-                                                        aminoethyl ester                                                          9   Sulphuric acid mono-N-(3-                                                                  3-Chloro-aniline                                                                         1-Hydroxy-2-                                                                           Acetic anhydride                                                                         yellow                            amino-6-chloro-phenyl-  methoxy-benzene                                       sulphonyl)-3-aminopropyl                                                      ester                                                                     10  Sulphuric acid mono-N-(2-                                                                  2-Amino-1-ethoxy-                                                                        Phenol   Ethyl chloride                                                                           yellow                            amino-4-chloro-phenyl-                                                                     benzene                                                          sulphonyl)-2-aminopropyl                                                      ester                                                                     11  Sulphuric acid mono-N-(2-                                                                  2-Amino-1,4-dieth-                                                                       1-Chloro-3-                                                                            p-Toluenesulphonyl                                                                       orange                            amino-5-chloro-phenyl-                                                                     oxy-benzene                                                                              hydroxy-benzene                                                                        chloride                                     sulphonyl)-3-aminobutyl                                                       ester                                                                     12  Sulphuric acid mono-N-(4-                                                                  2-Amino-toluene                                                                          o-Cresol 2,3-Butylene oxide                                                                       yellow                            amino-5-chloro-phenyl-                                                        sulphonyl)-N-phenyl-2-                                                        aminoethyl ester                                                          13  Sulphuric acid mono-N-(4-                                                                  2-Amino-1,4-di-                                                                          3-Hydroxy-                                                                             Propylene oxide                                                                          scarlet                           amino-2,5-dichloro-phenyl-                                                                 methoxy-benzene                                                                          diphenyl                                              sulphonyl)-N-ethyl-2-                                                         aminoethyl ester                                                          14  Sulphuric acid mono-N-(2-                                                                  Aniline    Phenol   Benzoyl chloride                                                                         yellow                            amino-3,5-dichloro-                                                           phenylsulphonyl)-2-amino-                                                     ethyl ester                                                               15  Sulphuric acid mono-N-(3-                                                                  3-Amino-anisole                                                                          4-Hydroxy-1,2-                                                                         n-Butyl-sulphonyl                                                                        yellow                            amino-4-methyl-phenyl-  dimethyl-benzene                                                                       chloride                                     sulphonyl)-N-cyclohexyl-                                                      2-amino-ethyl ester                                                       16  Sulphuric acid mono-N-(4-                                                                  2-Amino-4-methoxy-                                                                       1-Chloro-2-                                                                            n-Butyl bromide                                                                          orange                            amino-5-methyl-phenyl-                                                                     toluene    hydroxy-benzene                                       sulphonyl)-N-(3-methyl-                                                       phenyl)-2-aminoethyl ester                                                17  Sulphuric acid mono-N-(3-                                                                  3-Amino-toluene                                                                          1-Hydroxy-4-                                                                           Isobutylene oxide                                                                        orange                            amino-2,4-dimethyl-     ethyl-benzene                                         phenylsulphonyl)-2-amino-                                                     ethyl ester                                                               18  Sulphuric acid mono-N-(3-                                                                  Aniline    Phenol   γ-Phenoxy-propylene                                                                yellow                            amino-4,6-dimethyl-phenyl-       oxide                                        sulphonyl)-N-butyl-2-                                                         aminoethyl ester                                                          19  Sulphuric acid mono-N-(2-                                                                  1-Amino-naphthalene                                                                      m-Cresol Dimethyl sulphate                                                                        orange-                           amino-3,5-dimethyl-phenyl-                  red                               sulphonyl)-3-aminopropyl                                                      ester                                                                     20  Sulphuric acid mono-N-(4-                                                                  2-Amino-1,4-dimeth-                                                                      p-Cresol Butyryl chloride                                                                         orange                            amino-3-chloro-5-methyl-                                                                   oxy-benzene                                                      phenylsulphonyl)-2-amino-                                                     tert.-butyl ester                                                         21  Sulphuric acid mono-N-(2-                                                                  1-Amino-2-ethoxy-                                                                        m-Cresol --         yellow-                           amino-5-chloro-3-methyl-                                                                   benzene                        brown                             phenylsulphonyl)-2-amino                                                      ethyl ester                                                               22  Sulphuric acid mono-N-(3-                                                                  Aniline    o-Cresol Ethylene oxide                                                                           yellow                            amino-6-methyl-phenyl-                                                        sulphonyl)-N-methyl-2-                                                        aminoethyl ester                                                          23  Sulphuric acid mono-N-(4-                                                                  2-Amino-toluene                                                                          Phenol   Epichlorohydrin                                                                          yellow                            amino-5-ethoxy-phenyl-                                                        sulphonyl)-2-aminoethyl                                                       ester                                                                     24  Sulphuric acid mono-N-(3-                                                                  1-Amino-3-ethyl-                                                                         o-Cresol Styrene oxide                                                                            yellow                            amino-4-methoxy-phenyl-                                                                    benzene                                                          sulphonyl)-2-aminopropyl                                                      ester                                                                     25  Sulphuric acid mono-N-(3-                                                                  2-Amino-anisole                                                                          1-Chloro-4-                                                                            Methyl iodide                                                                            reddish-                          amino-4-methoxy-phenyl- hydroxy-benzene     tinged                            sulphonyl)-2-amino-propyl                   yellow                            ester                                                                     26  Sulphuric acid mono-N-(3-                                                                  5,6,7,8-Tetrahydro-                                                                      m-Cresol Propyl bromide                                                                           orange                            amino-6-methoxy-phenyl-                                                                    naphth-1-ylamine                                                 sulphonyl)-N-phenyl-2-                                                        aminoethyl ester                                                          27  Sulphuric acid mono-N-(4-                                                                  2-Amino-1,4-dimeth-                                                                      m-Cresol Dimethyl sulphate                                                                        scarlet                           amino-2-chloro-5-methoxy-                                                                  oxy-benzene                                                      phenylsulphonyl)-2-amino-                                                     ethyl ester                                                               28  Sulphuric acid mono-N-(3-                                                                  2-Amino-4-methoxy-                                                                       o-Cresol 3-Methyl-benzoic acid                                                                    yellow                            amino-5-chloro-4-methoxy-                                                                  toluene                                                          phenylsulphonyl)-N-methyl-                                                    2-aminoethyl ester                                                        29  Sulphuric acid mono-N-(3-                                                                  Aniline    Phenol   Diethyl sulphate                                                                         yellow                            acetylamino-6-amino-                                                          phenylsulphonyl)-2-amino-                                                     ethyl ester                                                               30  Sulphuric acid mono-N-(2-                                                                  2-Aminoanisole                                                                           o-Cresol 1,2-Butylene oxide                                                                       yellow                            amino-5-benzoylamino-                                                         phenylsulphonyl)-N-ethyl-                                                     2-aminoethyl ester                                                        31  Sulphuric acid mono-N-(3-                                                                  2-Amino-1,4-dimeth-                                                                      m-Cresol Ethylene oxide                                                                           scarlet                           acetylamino-6-amino-4-                                                                     oxy-benzene                                                      methoxy-phenylsulphonyl)-                                                     2-aminoethyl ester                                                        32  Sulphuric acid mono-N-(3-                                                                  2-Aminotoluene                                                                           Phenol   Dimethyl sulphate                                                                        yellow                            amino-4-bromo-phenyl-                                                         sulphonyl)-N-cyclohexyl-                                                      2-aminoethyl ester                                                        33  Sulphuric acid mono-N-(4-                                                                  Aniline    o-Cresol Propylene oxide                                                                          yellow                            amino-5-trifluoromethyl-                                                      phenylsulphonyl)-N-methyl-                                                    2-aminoethyl ester                                                        34  Sulphuric acid mono-N-(2-                                                                  2-Amino-4-methoxy-                                                                       m-Cresol Methyl chloride                                                                          orange                            amino-5-trifluoromethyl-                                                                   toluene                                                          phenylsulphonyl)-2-                                                           aminoethyl ester                                                          35  Sulphuric acid mono-N-(2-                                                                  2-Aminoanisole                                                                           o-Cresol Ethyl chloride                                                                           yellow                            amino-phenylsulphonyl)-                                                       N-cyclohexyl-2-aminoethyl                                                     ester                                                                     36  Sulphuric acid mono-N-(3-                                                                  2-Amino-4-methoxy-                                                                       o-Cresol Propylene oxide                                                                          orange                            amino-phenylsulphonyl-)N-                                                                  toluene                                                          phenyl-2-aminoethyl ester                                                 37  Sulphuric acid mono-N-(4-                                                                  Aniline    Phenol   Dimethyl sulphate                                                                        yellow                            amino-phenylsulphonyl)-N-                                                     methyl-2-aminoethyl ester                                                 38  Sulphuric acid mono-N-(3-                                                                  2-Amino-anisole                                                                          o-Cresol Diethyl sulphate                                                                         yellow                            amino-4-methyl-phenyl-                                                        sulphonyl)-2-aminoethyl                                                       ester                                                                     39  Sulphuric acid mono-N-(3-                                                                  2-Amino-1,4-dimeth-                                                                      p-Cresol 1,2-Butylene oxide                                                                       scarlet                           amino-4-methoxy-phenyl-                                                                    oxy benzene                                                      sulphonyl)-N-methyl-2-                                                        aminoethyl ester                                                          40  Sulphuric acid mono-N-(3-                                                                  2-Amino-anisole                                                                          Phenol   Methyl chloride                                                                          yellow                            amino-phenylsulphonyl)-3-                                                     aminopropyl ester                                                         __________________________________________________________________________

EXAMPLE 41

20 g of a dyestuff of the formula ##STR19## are introduced into 50 ml of96% strength sulphuric acid at 0°-5° C., whilst cooling. The mixture issubsequently stirred, first at 0`-5° C. for 1 hour and then at 15°-20°C. for 3 hours. The solution is then discharged onto about 300 ml ofice-water, the temperature being kept below 5° C. The dyestuffprecipitate is allowed to settle, the sulphuric acid solution is largelydecanted off, the product is filled up to a volume of about 200 ml withice-water, 50 g of sodium acetate are added, whilst cooling, and theresulting precipitate is filtered off. After washing and drying at 60°in a circulating air drying cabinet, about 20 g of a dyestuff of theformula ##STR20## which dyes polyamide scarlet from a weakly acid orneutral bath are obtained. The dyeing has a high level of fastness.

We claim:
 1. A disazo dyestuff which, in the form of the free acidcorresponds to the formula ##STR21## wherein R₁ denotes hydrogen, alkyl,alkyl substituted by fluorine, chlorine, cyano, hydroxyl, C₁ -C₄-alkoxy, phenoxy, C₁ -C₄ -alkylcarbonyloxy or phenyl, phenyl substitutedby C₁ -C₄ -alkoxy, chlorine, cyano, nitro or C₁ -C₄ -alkyl orcyclohexyl,R₂ denotes chlorine, bromine, alkoxy, alkoxy substituted byfluorine, chlorine, cyano, hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄-alkylcarbonyloxy or phenyl, alkyl, alkyl substituted by fluorine,chlorine, cyano, hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄-alkylcarbonyloxy or phenyl, acetylamino or benzoylamino, R₃ and R₄denote hydrogen, chlorine, bromine, alkoxy or alkyl, which alkoxy oralkyl can be unsubstituted or is substituted by fluorine, chlorine,cyano, hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄ -alkylcarbonyloxy orphenyl, R₅ and R₆ denote hydrogen, alkyl, alkoxy, chlorine or phenyl,which alkyl or alkoxy can be unsubstituted or is substituted byfluorine, chlorine, cyano, hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄-alkylcarbonyloxy or phenyl and which phenyl can be substituted by C₁-C₄ alkoxy, chlorine, cyano, nitro or C₁ -C₄ -alkyl, R₇ denotes alkyl,alkylcarbonyl, phenylcarbonyl, alkylsulphonyl or phenylsulphonyl, whichalkyl can be unsubstituted or is substituted by fluorine, chlorine,cyano, hydroxyl, C₁ -C₄ -alkoxy, phenoxy, C₁ -C₄ -alkylcarbonyloxy orphenyl and which phenyl can be substituted by C₁ -C₄ alkoxy, chlorine,cyano, nitro or C₁ -C₄ -alkyl, X denotes branched or unbranched C₂ -C₄-alkylene, B denotes 1,4-phenylene, 1,4-naphthylene ortetrahydro-1,4-naphthylene and m denotes a number from 0-2.
 2. Disazodyestuffs according to claim 1, which, in the form of the free acid,correspond to the formula ##STR22## wherein R₁ ' denotes hydrogen,methyl, ethyl or cyclohexyl,R₂ ' denotes chlorine, methoxy, methyl,ethoxy, ethyl, trifluoromethyl or acetylamino, R₃ ' denotes hydrogen,methyl, methoxy, ethyl and ethoxy, R₄ ' denotes hydrogen, methyl,methoxy, ethyl and ethoxy, R₅ ' denotes hydrogen, methyl, methoxy,chlorine or phenyl, R₆ ' denotes hydrogen or methyl, R₇ ' denoteshydrogen, methyl, ethyl, 2-hydroxyethyl, 2-hydroxypropyl and2-hydroxybutyl, m' denotes 0 or 1 and X has the meaning indicated inclaim
 1. 3. Disazo dyestuffs according to claim 1 which, in the form ofthe free acid, correspond to the formula ##STR23## wherein B' denotes1,4-naphthylene or tetrahydro-1,4-napthylene andR₁ ', R₂ ', R₅ ', R₆ ',R_(7') and m' have the meaning indicated in claim 2.